“C minor” – thus wrote the theorist Johann Mattheson in 1713 – “is a very lovely, but at the same time sad tone,” pointing out the remarkable spectrum attributed to this key at Bach’s time, when the aesthetics of key signatures usually ascribed only one character to any key. C minor is also the signature of the core pieces of Bach’s Musikalisches Opfer or Musical Offering, two large-scale solo works for harpsichord, which Bach purposefully entitled with the old-fashioned term Ricercare, an acronym and wordplay: Regis Iussu Cantio Et Reliqua Canonica Arte Resoluta (“The Theme Given by the King, with Additions, Resolved in the Canonic Style”). The other works of this programme are also dominated by the “royal theme” and the key of C minor, which – thus the general opinion in 1785 – encompassed “any languishing, longing, sighing of the lovelorn soul” (Schubart, Ästhetik der Tonkunst). At this time, Mozart published two piano works in C minor entitled Fantaisie et Sonate pour le Forte-Piano, characterised by a completely novel expression of subjective tragedy – Mozart’s manner of overcoming this in the third movement points forward to Beethoven. Beethoven, then, made his last piano work a Sonata in C minor – which mean-while became classified as “pathetisch” (Rochlitz, 1824) and was felt by many to be a work of farewell in two movements.